The initiation of the polymerization of acrylic monomers with peroxy esters bearing hindered amine light stabilizing substituents is described by P. A. Callais et al in a paper presented in February 1988 at the "Waterborne and Higher Solids Coating Symposium" in New Orleans and published in Modern Paint and Coatings, 78 (9), 41 (1988).
Peroxides as free radical initiators containing hindered amine moieties is described in European Patent Application No. 233,476.
The combination of ultraviolet stabilizers (UV absorbers) with free radical initiating moieties (azo derivatives and peroxide compounds) are disclosed in U.S. Pat. Nos. 3,956,269; 4,042,773; 4,045,426; 4,045,427; 4,055,714 and 4,129,586.
4,4'-Azo-bis(4-cyano-2,2,6,6-tetramethylpiperin-4-yl) and 4,4'-azo-bis(4-cyano-1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl) are disclosed as plastic additives in Chem. Abst. 79, 105051b.
The instant invention overcomes the drawbacks of the prior art materials which combine hindered amines with high basicity with peroxy groups.
The high basicity can neutralize acid catalysts that are commonly used in thermosetting resins thus causing cure inhibition. In other applications, the high basicity of many hindered amines can lead to undesired complexing and deactivation of metal ions which are used as catalysts for oxidative curing processes as well as undesired interactions with some pigment systems.